Alternator Problem - Maybe?

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johnsIslander

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I lost power to my radio and then lost my tach the speedometer on my 97 4Runner on Sunday. Wouldn't crank at first but jumped it and got it running. Wouldn't come out of park initially but once it did couldn't go more than 5mph in "limp-mode". Then all the sudden it began working as normal. Running normal for a few days without having to jumpstart until today at lunch. Lost tach pulled over and put in park. Didnt want to come out of park again but got it in gear and it's all back to normal. No jumpstart required or anything. Advance says my battery needs to be replaced but I'm skeptical?

Any thoughts? Thanks
 
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how many volts is the battery putting out with the truck off?

how many volts is the alternator putting out when the truck is running?
 
If you have a bad battery, any other troubleshooting is a waste of time. So borrow a battery if you don't trust the test or the tester. Any will do for a test.

Or find someone who can test it right. Pull it, charge it, load test it. If it fails, swap it.

Posting about this situation until you sort the battery issue is a waste of time.
 
i had a similar issue saturday, but i had noticed something earlier last week. the starter cranked very slow, but started. everything good until saturday morning. i went to start the truck, nothing. i'm thinking the starter, but the symptoms weren't there. i checked voltage at battery and it was 12.5 while off. i tried starting it again a bit later, and again, slow crank but it started. check voltage while running and reading was normal at 14.8. sunday afternoon it wouldn't start. i checked voltage and it was 10.8. figured there was a dead cell in the battery. i went back to where i bought it and since it was a 3 year battery, it was still under warranty so i got a fresh one at no charge and everything is fine. being in florida, the heat probably killed that cell and caused intermittent failure.
 
When it's acting up you need to check your battery voltage. As asked above what is your battery-charging voltage when everything is Ok?


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19963.4lsr5 said:
When it's acting up you need to check your battery voltage. As asked above what is your battery-charging voltage when everything is Ok?


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Click to expand...

Just static voltage testing doesn't tell you much about the battery. He needs to test under load after a full charge. And if you don't know the condition of the battery, the charge voltage is meaningless.
 
So here's the deal.

When a battery is going bad, there is a few ways it can do so. What is happening to you, sounds like a direct indication of a intermittent dead/shorted cell in the battery. When it shorts, it turns the battery into a very high resistive load. Which is likely talking more current from the alternator than what the truck needs to stay running. I'm willing to bet, that your battery cables are extremely hot when you notice these symptoms.

Replace your battery, before you melt down a cable (or battery) and lose your truck to an electrical fire.
 
If it is a dead cell in the battery you are going to kill your alt unless you replace it. A battery with a dead cell will never reach full charge, so the alt keeps itself at full output. Replace the battery.
 
TheDurk said:
Just static voltage testing doesn't tell you much about the battery. He needs to test under load after a full charge. And if you don't know the condition of the battery, the charge voltage is meaningless.
Click to expand...



I agree, checking the voltage when it's screwing up will hopefully show say 11.5v with the engine running. If he had a DC clamp on amp meter it be easy work. But most don't have something like. Alt pushing 60a at idle and voltage low would tell everything.


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I went had it tested again after work and the battery tested bad. Replaced the battery and now I'm getting the battery warning light. I've a rebuilt alternator on there now that's about a year old.
 
Check the voltage while its running and see how much the alt is putting out. Your rebuilt alternator may have shit the bed...
 
johnsIslander said:
I went had it tested again after work and the battery tested bad. Replaced the battery and now I'm getting the battery warning light. I've a rebuilt alternator on there now that's about a year old.
Click to expand...

You are now learning why I keep telling people to fix/rebuild their factory Densos rather than junk them to buy remans. They tend to crap out fast. I hope yours was not an easy fix, assuming it is the alt.

Now is when you need to check your static voltages at rest and with engine running. If running voltage at the battery is 13.5-14.5 alt is good and you need to check all your battery and alternator connections. Also check Alt-S fuse.
 
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I concur with what the [MENTION=10169]TheDurk[/MENTION] said. Rebuild your OEM Denso starter if possible. Worn brushes is a common reason the alternator will fail. Here's a video [MENTION=102606]infamousRNR[/MENTION] and I made of replacing the brushes on my alternator. https://youtu.be/71_kBhg6_-A
 
theesotericone said:
If it is a dead cell in the battery you are going to kill your alt unless you replace it. A battery with a dead cell will never reach full charge, so the alt keeps itself at full output. Replace the battery.
Click to expand...
johnsIslander said:
I went had it tested again after work and the battery tested bad. Replaced the battery and now I'm getting the battery warning light. I've a rebuilt alternator on there now that's about a year old.
Click to expand...

Looks a little too late for that. Sadly, this is yet another bad thing that can happen when you have a bad battery.
 
mtbtim said:
I concur with what the [MENTION=10169]TheDurk[/MENTION] said. Rebuild your OEM Denso starter if possible. Worn brushes is a common reason the alternator will fail. Here's a video [MENTION=102606]infamousRNR[/MENTION] and I made of replacing the brushes on my alternator. https://youtu.be/71_kBhg6_-A
Click to expand...

I realize this thread is old and dirty now, but I watched your video last night and was wondering what your thoughts are on the internal electronics inside the alternator? I think mine is about cashed as it floats around 12.9-13 at hwy speed with only the headlights and radio on besides the other issues I have going on. (see my never-ending thread: http://www.toyota-4runner.org/3rd-g...ns-tests-keep-resetting-not-ready-status.html)

Thanks very much for all the videos you guys do, I've learned a lot and definitely appreciate the time spent making them.
 
Hi guys, i have a 1996/97 Toyota Hilux surf gen3 with the 3.0l kzn185 intercooled engine it also has twin batteries.
My question is when the engine is running i presume there should be a voltage of around 13.5 volts going to the batteries like most cars. or have toyota got some sort of weird regulation going on?

Just trying to work out if my alternator is fooked.

Battery resting voltage (engine off) is around 11.6 to 12 volts So a little low but tring to work out of thats because of the alternator.
When running the battery voltage is around 12.5 to 12,7 volts but does not increase with rpm.

Also is it worth getting the 140amp upgrade alternator that is for sale on ebay or just stick with the 70amp from roughtrax.
 
HighlandsMatt said:
Hi guys, i have a 1996/97 Toyota Hilux surf gen3 with the 3.0l kzn185 intercooled engine it also has twin batteries.
My question is when the engine is running i presume there should be a voltage of around 13.5 volts going to the batteries like most cars. or have toyota got some sort of weird regulation going on?

Just trying to work out if my alternator is fooked.

Battery resting voltage (engine off) is around 11.6 to 12 volts So a little low but tring to work out of thats because of the alternator.
When running the battery voltage is around 12.5 to 12,7 volts but does not increase with rpm.

Also is it worth getting the 140amp upgrade alternator that is for sale on ebay or just stick with the 70amp from roughtrax.
Click to expand...

Can't be sure if it is battery, alternator or both. Pull battery, charge it correctly, load test and see what static voltage is then. If battery is good, then alt. is indeed fooked. But I'm thinking it is battery or maybe both.

Bad batteries kill alts and vice versa, so both bad happens a fair amount, especially if people don't address problems promptly.

Can't blame an alt. for not charging a sick battery, but it will die trying. Spec output is:

(b) Check the charging circuit as follows:
With the engine running from idling to 2,000 rpm, check
the reading on the ammeter and voltmeter.
Standard amperage: 10 A or less
Standard voltage:
At 25 °C (77 °F): 13.7 - 14.7 V
At 115 °C (239 °F): 13.2 - 14.0 V
Click to expand...

http://www.teamtoyota4x4.org/archivio/1996%20to%202002%20Toyota%204Runner%20Repair%20and%20Wiring%20Manuals/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/ch5vzfe/chasy/ovi.pdf
 
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Hi guys just an update,
Got the alternator issue fixed

Turns out the brushes were the cause of the low charging.

Now charging at 13.4 to 13.6 volts

Happy surf again :-)
 
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